Fracturing involves high flow rates and pressures to open up a formation using specialized fluids for the task. Typically after enough fluid volume at high enough pressure to fracture the formation is pumped, proppant is then added to the fracture fluid to enter the fractures just made and hold them open for subsequent production. In some applications, a screen assembly is introduced or is already in the well when the fracturing occurs. The fracturing process then transitions into a gravel packing process to allow proppant to fill the screen/casing annulus thus completing the gravel pack portion of a frac packed completion. When the proppant is introduced below an isolation packer for a given interval in a zone, it crosses over into the annulus surrounding the screens so that it can enter the fractures as well as fill the annular space around the screen assembly before production. The proppant is delivered into the fractures at high pressures and injection rates. The pump rates are reduced and circulation allowed to occur in order to fill the annulus between the screen and casing to complete the gravel pack.
In the past, fracturing and gravel packing of very long zones or multiple zones, whether in open hole or in cased hole typically required intermediate isolation packers to subdivide the interval into smaller zones to focus the fracturing or the gravel packing into such subdivided zones. This was time consuming and expensive because it required more packers, generally more trips in the well bore to facilitate equipment placement, and forced the same operation to be repeated numerous times to properly prepare an entire interval for subsequent production.
What is needed and provided by the present invention is a way to gravel pack the entire screened interval in a single operation in cased or open hole and then still have the ability to isolate intervals within a gravel packed zone for fracturing in a desired order through selectively opened ports in a liner. Another need addressed by the invention uses telescoping members that can be extended so that an annular space can be bridged by them while a liner is cemented, for example. Some of the telescoping members can be subsequently used for production. Some telescoping members in a liner can be associated with a valve and selectively opened in any desired order for a fracturing operation localized to the region around the telescoping members with its associated valve being opened. Production can then take place through the telescoping members with screens built into them while the other telescoping members that were used for fracturing have their associated valves closed.
Telescoping members have been in use to provide formation access after an annular space is cemented. These members have been equipped with either rupture discs or some other blocking material that can disappear such as by chemical interaction to open up a passage for flow after extension and cementing of the surrounding annulus. A good example of this is U.S. Pat. No. 5,829,520 as well as the various Zandmer patents cited in that patent. Gravel packing with zone isolation already in place in combination with bypass tubes to let the gravel get past such set barriers is shown in U.S. Pat. No. 5,588,487.
The preferred embodiment of the present invention will illustrate exemplary concepts of completions involving cementing and fracturing with a possible use of gravel packing in a procedure that optimizes the completion to allow it to get done faster and in a more cost effective manner. These and other advantages will become more readily apparent from a review of the description of the preferred embodiment and the associated drawings while recognizing that the appended claims define the full scope of the invention.